The term beta movement is used for the optical illusion of apparent motion in which the very short projection of one figure and a subsequent very short projection of a more or less similar figure in a different location are experienced as one figure moving.
The illusion of motion caused by animation and film is sometimes believed to rely on beta movement, as an alternative to the older explanation known as persistence of vision. However, the human visual system can't distinguish between the short-range apparent motion of film and real motion, while the long-range apparent motion of beta movement is recognised as different and processed in a different way.[1]
